Since the development of tuned circuits, various types of energies such as electricity, light, and electromagnetism have been used to transmit various forms of stimuli, improving the quality of every day life. The stimuli transmitted from tuned circuits may be in the form of sound, e.g. phones and stereos, or in the form of light, e.g. television and data via a computer monitor. Such elements have enabled businesses as well as families to communicate with other counterparts across the globe conveniently and virtually without delay, resulting in closer bonds.
Tuned circuits have recently been introduced to semiconductor integration technologies. Though semiconductor technology has advanced in virtually every possible way, there is still difficulty when implementing tuned circuit technology. It has been very difficult to integrate large tuned circuit elements without sacrificing frequency extraction capabilities or quality factor (“Q-factor”).
An important tuned circuit element making the previously mentioned systems possible is the inductor. Inductors can have a respectively low frequency response, thus they can be utilized for low frequency extraction or limiting, depending on the configuration. Using inductors along with other circuit components make it possible to receive, extract, process, manipulate, and transmit information in the form of energies coving a broad spectrum of frequencies.
Recently, on-chip inductors have been introduced to the semiconductor fabrication process for integration. This process has experience some difficulties. Inductors are essentially a coil of wire or some electrically conductive material. Generally, as the size shrinks, so does their inherent inductance quality factor. Therefore, integrated inductors have respectively low inductances.
Including inductors in semiconductor technologies is also difficult due to the electromagnetic interference generated therein. The fields generated by one circuit element tends to interfere with the signals within other adjacent circuit elements. Additionally, inductors in semiconductor technology tend to couple fields to the substrate inducing Eddy currents within the substrate.